All of lore.kernel.org
 help / color / mirror / Atom feed
From: Daniel Vetter <daniel@ffwll.ch>
To: Kangjie Lu <kjlu@umn.edu>
Cc: pakki001@umn.edu,
	Rodrigo Siqueira <rodrigosiqueiramelo@gmail.com>,
	Haneen Mohammed <hamohammed.sa@gmail.com>,
	Daniel Vetter <daniel@ffwll.ch>, David Airlie <airlied@linux.ie>,
	dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2] drm: vkms: check status of alloc_ordered_workqueue
Date: Mon, 25 Mar 2019 09:31:19 +0100	[thread overview]
Message-ID: <20190325083119.GB2665@phenom.ffwll.local> (raw)
In-Reply-To: <20190323214216.10824-1-kjlu@umn.edu>

On Sat, Mar 23, 2019 at 04:42:16PM -0500, Kangjie Lu wrote:
> alloc_ordered_workqueue may fail and return NULL.
> The fix cleans up drm plans and returns ENOMEM when it fails to
> avoid potential NULL pointer dereference.
> 
> Signed-off-by: Kangjie Lu <kjlu@umn.edu>
> ---
> V2: clean up resources
> ---
>  drivers/gpu/drm/vkms/vkms_crtc.c | 11 +++++++++++
>  1 file changed, 11 insertions(+)
> 
> diff --git a/drivers/gpu/drm/vkms/vkms_crtc.c b/drivers/gpu/drm/vkms/vkms_crtc.c
> index 8a9aeb0a9ea8..018b52dd953a 100644
> --- a/drivers/gpu/drm/vkms/vkms_crtc.c
> +++ b/drivers/gpu/drm/vkms/vkms_crtc.c
> @@ -219,6 +219,17 @@ int vkms_crtc_init(struct drm_device *dev, struct drm_crtc *crtc,
>  	spin_lock_init(&vkms_out->state_lock);
>  
>  	vkms_out->crc_workq = alloc_ordered_workqueue("vkms_crc_workq", 0);
> +	if (!vkms_out->crc_workq) {
> +		ret = -ENOMEM;
> +		goto cleanup;
> +	}
> +
> +	return ret;
>  
> +cleanup:

Style nit for the future, for clarity I'd label this err:, since this path
is only taken for failures, and not to do cleanup for all cases.

Aside from that, I think your v1 was correct, vkms_crtc_init only sets up
the crtc, it doesn't allocate the cursor/planes. That's done from
vkms_output_init, which already has the cleanup code to handle this case.
-Daniel

> +	if (!IS_ERR_OR_NULL(cursor))
> +		drm_plane_cleanup(cursor);
> +	if (!IS_ERR(primary))
> +		drm_plane_cleanup(primary);
>  	return ret;
>  }
> -- 
> 2.17.1
> 

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch

WARNING: multiple messages have this Message-ID (diff)
From: Daniel Vetter <daniel@ffwll.ch>
To: Kangjie Lu <kjlu@umn.edu>
Cc: Haneen Mohammed <hamohammed.sa@gmail.com>,
	Rodrigo Siqueira <rodrigosiqueiramelo@gmail.com>,
	David Airlie <airlied@linux.ie>,
	linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org,
	pakki001@umn.edu
Subject: Re: [PATCH v2] drm: vkms: check status of alloc_ordered_workqueue
Date: Mon, 25 Mar 2019 09:31:19 +0100	[thread overview]
Message-ID: <20190325083119.GB2665@phenom.ffwll.local> (raw)
In-Reply-To: <20190323214216.10824-1-kjlu@umn.edu>

On Sat, Mar 23, 2019 at 04:42:16PM -0500, Kangjie Lu wrote:
> alloc_ordered_workqueue may fail and return NULL.
> The fix cleans up drm plans and returns ENOMEM when it fails to
> avoid potential NULL pointer dereference.
> 
> Signed-off-by: Kangjie Lu <kjlu@umn.edu>
> ---
> V2: clean up resources
> ---
>  drivers/gpu/drm/vkms/vkms_crtc.c | 11 +++++++++++
>  1 file changed, 11 insertions(+)
> 
> diff --git a/drivers/gpu/drm/vkms/vkms_crtc.c b/drivers/gpu/drm/vkms/vkms_crtc.c
> index 8a9aeb0a9ea8..018b52dd953a 100644
> --- a/drivers/gpu/drm/vkms/vkms_crtc.c
> +++ b/drivers/gpu/drm/vkms/vkms_crtc.c
> @@ -219,6 +219,17 @@ int vkms_crtc_init(struct drm_device *dev, struct drm_crtc *crtc,
>  	spin_lock_init(&vkms_out->state_lock);
>  
>  	vkms_out->crc_workq = alloc_ordered_workqueue("vkms_crc_workq", 0);
> +	if (!vkms_out->crc_workq) {
> +		ret = -ENOMEM;
> +		goto cleanup;
> +	}
> +
> +	return ret;
>  
> +cleanup:

Style nit for the future, for clarity I'd label this err:, since this path
is only taken for failures, and not to do cleanup for all cases.

Aside from that, I think your v1 was correct, vkms_crtc_init only sets up
the crtc, it doesn't allocate the cursor/planes. That's done from
vkms_output_init, which already has the cleanup code to handle this case.
-Daniel

> +	if (!IS_ERR_OR_NULL(cursor))
> +		drm_plane_cleanup(cursor);
> +	if (!IS_ERR(primary))
> +		drm_plane_cleanup(primary);
>  	return ret;
>  }
> -- 
> 2.17.1
> 

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel

  reply	other threads:[~2019-03-25  8:31 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-03-09  4:36 [PATCH] drm: vkms: check status of alloc_ordered_workqueue Kangjie Lu
2019-03-23  2:32 ` Kangjie Lu
2019-03-25  8:34   ` Daniel Vetter
2019-03-25  8:34     ` Daniel Vetter
2019-03-23 10:05 ` Mukesh Ojha
2019-03-23 21:42   ` [PATCH v2] " Kangjie Lu
2019-03-25  8:31     ` Daniel Vetter [this message]
2019-03-25  8:31       ` Daniel Vetter

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20190325083119.GB2665@phenom.ffwll.local \
    --to=daniel@ffwll.ch \
    --cc=airlied@linux.ie \
    --cc=dri-devel@lists.freedesktop.org \
    --cc=hamohammed.sa@gmail.com \
    --cc=kjlu@umn.edu \
    --cc=linux-kernel@vger.kernel.org \
    --cc=pakki001@umn.edu \
    --cc=rodrigosiqueiramelo@gmail.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.